1. Field of the Invention
The present invention relates to antenna devices for use in remote control devices that communicate with portable devices and remotely control locking/unlocking of vehicle doors and the like.
2. Background Art
Recently, remote control devices for remotely controlling locking/unlocking of vehicle doors based on communication between a vehicle-borne antenna device and a portable device are becoming widely used.
Referring to FIG. 5, description of a conventional antenna device used in such remote control devices will be given.
FIG. 5 is a sectional view of a conventional antenna device. In FIG. 5, nearly box-like case 101 made of a nonconductive material is formed with opening 101A provided on the top face and with lead terminals 102A, 102B integrally formed and embedded on a left side face.
Antenna member 103 consists of core 103A, coil 103B and capacitor 103C. Starting end of coil 103B wound on the outer periphery of core 103A is connected to lead terminal 102A while end of winding of coil 103B is connected to one end of capacitor 103C. The other end of capacitor 103C is connected to lead terminal 102B. Case 101 houses antenna member 103 within itself.
Also, each of lead terminal 102A and lead terminal 102B is connected to lead wire 105 outside of case 101 by pressure bonding, for example. Here, each of the connecting sections of lead terminal 102A, lead terminal 102B and lead wire 105 is covered with heat-shrinkable tube 109 to prevent from being exposed to outside.
Furthermore, a connector (not shown) provided behind lead wire 105 and a connector to be coupled of a vehicle-borne device (not shown) are trunk connected. Here, for the convenience of description, the right side of FIG. 5, namely the side of antenna member 103, is referred to as main body section 110A and the left side, namely the side of lead wire 105, is referred to as wiring section 110B.
Also, filler 106 such as silicone resin or epoxy resin is filled to seal in antenna member 103 inside case 101. Filler 106 is subsequently hardened at a predetermined temperature and antenna member 103 is secured inside case 101.
Subsequently, locking holes 104A provided on the sides of lid 104 having an opening on its lower face are engaged with nails 101B of case 101, thus covering opening 101A of case 101 with lid 104 and completing antenna device 110.
In the above configuration, main body 110A of antenna device 110 is disposed inside a door handle of a vehicle door. Wiring section 110B pulled out from within the door handle is wired inside a space formed between exterior chassis of the vehicle door and interior rubber of the vehicle door. At the same time, posterior portion of wiring section 110B is connected with the vehicle-borne device by transmit connection.
Radio signal communication is conducted between a portable device (not shown) carried by a user and the antenna device 110, and the vehicle-borne device identifies the signal received from antenna device 110 and remotely operates locking and unlocking of vehicle doors.
As conventional art information relating to the invention of this patent application, Japanese Unexamined Patent Application Publication No. 2001-345615, for example, is known.
However, with such conventional antenna device 110 as described above, it is necessary to adjust the length of lead wire 105 of wiring section 110B in accordance with the type of vehicle or the position of disposing antenna device 110. Accordingly, the conventional device has problems of requiring many components, complication in manufacturing, and increase in the types of antenna device 110.